The overall objective of our research is to answer the fundamental questions raised by the use of viruses to control "pest" insects and disease vectors:

i) what are the mechanisms involved in the virus-host interaction,
ii) what determines viral specificity and how do viruses adapt to new hosts
iii) what is the prevalence and diversity of insect-associated viruses and how do viruses circulate in natural and “anthropized” ecosystems.

We are virologists, particularly interested in the potential of insect parvoviruses (densoviruses) to control insects causing damage in agriculture or health. To answer the fundamental questions posed by their use, we are developing an integrated research framework to study virus-host interactions at different scales, from molecules to insect and virus populations.

Our model of host-virus interaction consists of phytophagous caterpillars belonging to the genus Spodoptera (S. frugiperda and S. littoralis) and for the virus, Junonia coenia densovirus (JcDV) is our model and the type species of the genus Ambidensovirus.

Spodoptera sp. is a complex of 30 species threatening crops around the world. S. frugiperda was until recently restricted to the Americas. This polyphagous species was introduced to Africa in 2016 and is now spreading to many countries and various cropping systems.

Densoviruses are small, linear, single-stranded DNA viruses, which makes them belong to the Parvoviridae family. They are among the smallest known animal viruses (18-26 nm) and they were discovered in insect farms in 1964. JcDV was discovered in 1972, during epizootics in lepidoptera populations in the United States (Berkeley, Long and Rivers area, 1972). It owes its name to that of its host, but it is also pathogenic for S. frugiperda and we have many tools to dissect its functioning, making this virus an excellent model for studying questions of fundamental virology.